This invention patent refers to an electronic system developed so as to command a matrix for the reproduction of video images in real time through pixels (image elements) in a way that the image reproduced on the matrix has the same advantages and the same attitude of the conventional cathodic ray tubes that is it may display composite video images in real time without the previous processing of analog/digital or digital/analog converters, without the need for microprocessors, digital memories, shift registers or even computers and converters which are normally needed so that images could be generated on a pixel matrix.
The display of information under the form of dynamic image when this is obtained by means of electronic reception or storage has been performed with a device called kinescope for more than 70 years.
The kinescope is a glass device with thick walls, large dimensions and heavy, able to stand the external pressures once there is vacuum inside; the basic principle is to reproduce an image by means of an electron beam that sweeps a screen embedded with phosphorus oxide and other elements, producing light during a time lapse according to the speed and quantity of electrons that hit the mentioned screen. The beam sweeping is controlled electrically or magnetically and is obtained by means of external analog devices, it is also necessary a high voltage producing device (approximately 25,000 volts) to accelerate the electrons inside the tube. Even though all the technology developed and available all over the world, it has not yet been possible to produce a device that could substitute the kinescope for television sets and/or computer monitors with the same image quality, cost and performance.
This is due mainly because inside the kinescope the image is generated analogically, the image resolution is not limited by a fixed number of pixels and/or light intensity once the resolution and image quality depend on the passing band of the circuit through which the video signal is transmitted rather than the kinescope itself as an image reproduction element. Cathodic ray kinescopes present the inconvenience of the size limit due to the need of very high tension to be generated (the larger the kinescope the higher the tension needed) and due to image convergence difficulties. In the last 70 years, because of these reasons commercially speaking, the size of kinescopes did not go much beyond 37″ diagonally.
However, with the advent of liquid crystals and advances in the development of photoluminescent displays and associated technologies, we have nowadays computer monitors and even television sets of very light weight that consume less energy and are competitively priced. Yet when we talk about image quality we must consider what is the objective, for instance if we talk about a PC which display image is in general static and with a defined number of pixels and light hues, generally 16, 32, 256, etc. there is no problem, but when we speak about televisions with 100% dynamic images producing around 60 frames per second and with a resolution that changes constantly needing moreover a viewing angle of 120° it is totally different; limitations regarding transmission speed due to digitalisation of the image, level of luminosity and narrow viewing angle are a great disadvantage, the latter almost discards the production of large dimension liquid crystal monitors in substitution of kinescopes in commercial television sets.
There is another kind of monitor utilising LED's (light emitting diodes), these generally of large dimensions, destined to be used as electronic outdoor billboards for publicity (also called electronic panels) the working principle is very much the same of the liquid crystal one, the Principle of Image Digitalisation; according to this principle any image or drawing that we wish to display may be digitally recorded or converted like computers that use the binary 100101 to represent the number 37, we may use the same binary 100101 to represent a colour or a light intensity onto a determined point of the display that has its moment authorised by the matrix coordinates in a logical and precise manner. Thus the image is always static and previously known.